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Extension foundations built with ground screws
Extension Foundations

Extension Foundations. Without the Mess.

Building a timber-framed extension or granny annexe? Ground screws bypass the disruption of deep-trench concrete — engineered to spec, installed in a day, ready to build on immediately.

Most jobs in 1 day
35-year guarantee
Across the Midlands
Get a Free Site Survey Call +44 7395 867441

Why Builders Choose Ground Screws for Extensions

Six reasons architects and builders trust us with their extension foundations.

Engineered to spec

Each foundation specified to your extension's loads, build method, and ground conditions.

Minimal garden disruption

No trenches, no spoil heaps, no concrete trucks. Your garden survives intact.

Fast-track your build

No 3-7 day concrete cure. The frame can be erected the same day.

Cost-effective

Often more cost-effective than equivalent concrete strip foundations, especially on awkward sites.

Works on any site

Sloping plots, restricted access, listed-building neighbours — we deliver where concrete trucks can't reach.

Annexes & granny pods

From 20m² studio annexes to full self-contained dwellings.

From Survey to Solid

Engineering Survey

We work with your builder, architect, or structural engineer to spec the right screw size, depth, and quantity for your specific extension.

Engineered Quote

Fixed-price quote within 24 hours, with installation date, screw spec, and load capacity for your extension's footprint.

One-Day Install

Our team installs each screw to the agreed grid layout, typically 1-2 days for a standard single-storey extension.

Hand-Over

Every cap left perfectly level. Your frame can be erected directly onto the screws the same day. No cure time, no waiting.

Extension Foundations: Ground Screws vs Concrete Strip.

Concrete Strip

  • Deep trenches required
  • Skip and spoil removal
  • Garden access destroyed by spoil and trucks
  • 3-7 day cure before frame can go up
  • More expensive on sloping sites

MW Ground Screws

  • No excavation needed
  • No spoil to dispose of
  • Garden access preserved
  • Frame can be erected same day
  • Better-value on tricky sites
See the full comparison
Single-storey extension supported on galvanised ground screws
WHAT TO EXPECT

How We Build An Extension Foundation.

Sized to your buildNo excavation, no spoil35-year guarantee

An extension foundation is engineered to the structure above it, so the screw count and spacing are set from your plans rather than a fixed formula. Ground screws come into their own on sloping plots, made-up ground or sites with restricted access, where a traditional trench-and-concrete footing is slow and disruptive. In many cases the foundation can be installed in a day with no excavation and no spoil to cart away, letting the frame go up soon after — all backed by our 35-year structural guarantee.

Read our reviews

Extension Foundations Across Our Six Counties.

Service Area
Shropshire
ShropshireWorcestershireWest MidlandsCheshireStaffordshirePowys

Extension Foundations: Frequently Asked Questions

Are ground screws suitable for extensions?
Yes — particularly timber-framed and lightweight extensions. For heavier masonry extensions we work alongside the structural engineer to confirm the load spec works.
What size extension can ground screws support?
Typical domestic extensions up to two storeys are well within ground screw capabilities. For larger or heavier builds we provide engineered specs and load calculations.
Do extensions on ground screws need planning permission?
Same rules as any extension — depends on the build size, height, and your local planning authority's permitted development rules. The foundation method doesn't affect the planning answer.
How does this compare to traditional concrete strip foundations?
Faster (hours vs days), cleaner (no spoil), often cheaper, and removable if needed. Concrete is still the right answer for some builds — but for most timber-framed extensions and annexes, ground screws are the better fit.
Can I build a granny annexe entirely on ground screws?
Yes — modular and timber-framed annexes sit very well on screw foundations. We've worked on annexe projects from 20m² granny pods through to full self-contained dwellings.
What about extensions next to listed buildings or in conservation areas?
Ground screws are often preferred in these settings — less ground disturbance, lower visual impact, fully reversible. Perfect for heritage properties where minimal intervention is required.
Does my builder need any special equipment to work with ground screw foundations?
No — once the screws are installed and capped, the build proceeds exactly as any other foundation. Your builder works with the screws just like they would with concrete pads or strip foundations.
What's the longest extension you've foundationed on screws?
We've delivered up to 60m² single-storey extensions and 40m² two-storey annexes on screws. Larger builds are possible — we engineer the foundation to the specific load requirements.
BUILT TO OUTLAST

35 years guaranteed.
~60 years engineered.

Every screw under your extension is backed by a 35-year structural guarantee. Hot-dip galvanised steel construction, designed to outlast the extension it supports.

  • Hot-dip galvanised steel
  • Engineered to load spec
  • Documented at installation
Discuss Your Extension

Ready to start your extension?

Free site survey within 48 hours. Fixed-price quote within 24 hours. 35-year guarantee on every install.

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